Two-part mine prop



TWO-PART MINES PROP 4 Sheets-Sheet 1 Filed Oct. 24, 1957 ril -il Sept.20, 1960 w. L. G. HEUSNER 2,953,343

TWO-PART MINE PROP Filed 001;. 24, 1957 4 Sheets-Sheet 2 Fig. 6

3+ E165 16b 32 r t I 29a y I ll j PI .6 a

32 f? so w. G. HEUSNER; 2,953,343

r Sept. 20, 1960 TWO-PART MINE PROP Filed Oct. 24, 195'? 4 Sheets-Sheet3 Sept. 20., 1960 w. L. s. HEUSNER 2,953,343

' TWO-PART MINE PRoP Filed Oct. 24, 1957 4 Sheets-Sheet 4 elas i def rmaon of he lock me t.

United States Patent g TWO-PART MINE PROP Wilhelm Liidwig GiistavHeiisner, Bochum-Weitmar, Germany, assignor to Hermann Schwarz K.GWattenscheid, Germany Filed Oct. 24, 1957, Ser- No. 592,152.

10 Claims. (Cl. 248-354) The present invention relates to a two-partmetallic mine prop. With mine props of this type it is common knowledgeto fix the two prop members, an upper prop member andv a lower propmember, relative toc leh other in operating position by means of apropfllock, while for purposes of robbing or abstracting the prop, thetwo prop members are released' o ha they can t l s op relativeto eachother.

With .most two-part metallic mine props, the prop members are heldrelative to eachother in their supporting position by a frictional forcepreventing the sinking .ofthe upper prop member. This frictional-forcedepends on the trictional surfac of said two prop ember .which are infrictional engagement with each other and also on h pres ur a which vsai,fri tional surf c s ar p essed against eachlother, said press r gnerally bein pro uced by the e astic f rma ion of one or a plurali y oflocking m nts. Thus, he magnitude f. th triotion l f rce is among othersdependent on the obta n- .ment vof a certain degree of deiormation ofthe lqclging j elemen du ng e t htening of the lo k.-

In order that the supporting ability .will be at least app imat lyuniform f r all mine props in talled at the s m w rking s at on, it isne essary to apply n ,fo fo ce to ea hm ne pr pin orderto ob ain unif rmIf he e asti deformation of the locking elements 'is obtained by wedgemeans, it is necessary to d iv he locking wedges at, h

{a force that the same endcondition will be obtainedwith each. mine propattthe same-working station. ,viousthat such a condition cannot berealizedin view-of It is ob- .the actthat-it is impossible forhuman'bei-ngs, to develop s h fine dis riminati fe l. partic l rly sincealso ditferences in thematerial of therespective looking elements areunavoidable.

It is, therefore, an object of the present invention to provide atwo-part mine prop, in which the elastic de-v vformation of the lockingelementswill be approximately the same with all mine props installed atthe same working station.

.It is another object of thisinvention to provide a mine .prop of thetype set forth in the precedingparagraph, in which the prop members ofeach mine prop will be held in their finally set position by amechanical latching mechanism. It is another object of this invention toprovideatwopart rnine prop, in which the pr P members can be .clampedagainst each other at acertainpreeisely defined predetermined pressureby means of a clamping ring connecting the upper prop member with thelower prop -.membe or b g g ab u ction a em t betw en t ejupn n lowerProp' m m rs. i

It is still another objec of this .inventior so to design .a cl mping rn r. c amp e uppe and. .low e q p q tem ersota m n Pr together th t; thetri tiona prestsure at'wh ch the inner s rfac h clamp ng n acts upon theupper prop member will have at least Patented Sept. 20,

nearly uniform pressure along the entire circumf,erence of said clampingring.

It is a further object of this invention so to design the frictionalpressure producing means for a two-part mine prop that said frictionalproducing means may selectively be detached from the mine prop to reducethe weight of the mine prop.

These and other objects and advantages of the invention. will appearmore clearly from the following specification in connection with theaccompanying drawings,

:in which:

Fig. 1 diagrammatically illustrates the front view of a mine prop with aclamping ring according to the invention.

Fig. 2 isia side view of the mine prop shown in Fig. 1

Fig. 3 is a section taken along the line HI-III of Fig. 1. t

Fig. 4 is a vertical section taken along the line IVIV of Fig. 3.

Fig, 5 is a horizontal section through a mine prop similar to thatofFig. 3 but on a larger scale than the :latter and equipped with aclamping ,pressure produc ing device.

Fig. 6 is a side view of a modified clamping lock, showing the lockingmechanism in open position.

Fig, 6a is a view similar to that of Fig. 6 but with the lockingmechanism in locked or latched condition. Fig. 7 is a top view of Fig.6.

terized primary :in that the parts of the mine prop in working conditionof the latter are while elastically deforming the same tightenedrelative to each other and .are mechanically latched, while thetightening of the lock is eifected by a fluid pressureoperable device.The

actuating fluid may be in gaseous or liquid condition. As actuatingfluid or pressure medium among others compressed air may be used whichis amply available-in mining installations. If desired, however, thepressure :fluid means may be compressed by means of a cor-respondingpump. Also water or oil may be employed as pressure fluid. In someinstances the pressure in the strut .water line will suflicein order toproduce the power in the fluid pressure operable device for producingthe tightening action.

When the fluid pressure operable tightening devicehas brought about thedesired elastic deformation and thereby the required tightening of thelock, the latching of the lock iseifected mechanically. Locking meanstothis end may comprise a wedge, a clamping screw, or other adjustablelocking means. After such locking means have become effective, thepressure fluid in the fluidpressure operabledevice may be releasedtherefrom.

In order to be able at high precision to maintain the lockingtensionproduced by the fluid pressure operable device and to do so byamechanical latchingmechanisrn, the arrangement is in conformity with afurther, develop- .ment of the invention so selected. that with .a ti0.13 3 70.

mine prop according toethe invention, the fluidpressure operableclampingdevice ,will attack at the tlockin the same plane as the device employedfor latching the lock under tension. In this way it will be possibleprecisely to maintain the clamping effect in the lock obtained by thehydraulic clamping device, at precisely the adjusted value withoutrunning the risk that when lowering the hydraulic pressure or whenremoving the clamping device, a change in the clamping condition willoccur.

A Very important field of employment of the present invention is theemployment of such two-part mine props .in which the upper prop memberand also the lower prop member are in frictional engagement with eachother through the intervention of a clamping ring connected to the lowerprop member. Preferably, the upper prop member as well as the lower propmember are designed as hollow cylinders or hollow cylindrical tubes. Thetightening of the clamping ring is with a mine prop of the abovementioned type effected by pulling toward each other the two earsconnected to or forming a part of the free ends of the clamping ring.The forces exerted upon the ears when tightening the clamping ring firstact in circumferential direction. By means of the ring, the said forcesare split up in radially directed force com ponents which produce theimportant frictional pressure for tightening the mine prop membersrelative to each other. This frictional pressure should be substantiallyuniform along the circumference of the clamping ring. In order to obtainthis goal, in conformity with the present invention, the clamping ringis so designed that its cross section beginning from the ends increasesgradually toward the center in the manner of a girder of uniformresistance. In this way, the forces acting upon the ends of the clampingring are sub-divided and distributed over the entire prop circumferenceto produce a uniform frictional pressure. While the fluid pressureoperable clamping device contracts the clamping ring at the ends thereofto an ever increasing extent, the deforming forces exerted :in this wayupon the clamping ring are distributed in such a way that at the endcondition of the tightening operation, a uniform frictional pressure isexerted upon the upper mine prop member. This tensioning condition isthen maintained by making the mechanical latching means effective forthe entire period in which the mine prop occupies its working position.

Structural arrangement Referring now to the drawings in detail and Figs.1 to 5 thereof in particular, the mine prop shown therein comprises atubular lower prop member telescopically engaged by an upper tubularprop member 11. The prop member 10 is provided with a foot 12 while theupper prop member 11 is provided with a head 13. The device furthermorecomprises a clamping ring 14 the free ends of which have connectedthereto cars 16 and 16a. The lower prop member 10 and the clamping ring'14 are connected to each other by a band 15 connected to said clampingring and said lower prop member 10 in any convenient manner for instanceby welding.

As will be evident from Figs. 3 and 5, the thickness of the clampingring increases in a continuous manner from the ears 16 and 16a towardthat portion which is diametrically opposite the gap between said ears.The height of the clamping ring is the same along the entirecircumference thereof as is particularly clearly shown in Figs. 1 and 2.The increase in the cross section from the ears 16, 16a toward thatportion of the clamping ring which is diametrically opposite the gapbetween the ears 16, 16a is such that the strength of the clamping ringis substantially uniform throughout the same in the manner of a girderof even strength. Such an arrangement brings about the advantage thatthe force exerted upon the ends of the clamping ring is split up intosuch radial force components that the frictional pressure exerted by theclamping ring 14 upon the tubular upper prop member 11 will haveapproximately the same value throughout the circumference of theclamping ring when the latter is in clamped condition.

With the arrangement according to Figs. 1 to 5, the cars 16 and 16aincrease in thickness from their connecting point with the clamping ring14 towards the outside, their lateral surfaces 17 being inclined asshown in Fig. 4. The said ears are provided with grooves 18 adapted tobe engaged by the jaws 22 of the plier-like arnanged 'arms 21 and 21awhich are pivotally connected to each other by a pivot 20. The outerends of the arms 21 and 21a are pivotally connected by pivots 23a and24a to ears 23 and 24 respectively. The ear 23 is connected to apressure cylinder 25, whereas the ear 24 is connected to a piston rod 50which in its turn is connected to the piston 26 reciprocably mounted inthe pressure cylinder 25. The cylinder 25 communicates with a pipe 27. Arelief valve 28 is interposed between the pipe 27 and the cylinder 25.

When the mine prop has been adjusted as to height and when the clampingring is to be tightened, the jaws 22 of the arms 21, 21a are caused toengage the recesses 18, and pressure fluid is conveyed to the cylinder25 through pipe 27 and valve 28. As a result thereof, the clamping ringis contracted. The piston 26 moves relative to the cylinder 25 until acertain maximum pressure has been established within the cylinder pistonsystem 25, 26 which maximum pressure is determined by the setting of therelief valve 28. The trapezoidal wedgeshaped body 19 drops during thetightening operation effected by the clamping ring from the positionshown in Fig. 1, which position corresponds to the open position of theclamping ring, into the position shown in Fig. 4 along the inclinedsurfaces 17 of the clamping ring. Thus, the lock when in tightenedcondition is latched by the member 19. When relieving the fluid from thecylinder piston system 25, 26, the plier-like device 21, 21a can beopened and can be withdrawn from the cars 16, 16a of the clamping ring,while the mine prop remains in operative position in View of the lockingby the member 19.

When robbing or abstracting the mine prop, it is merely necessary toknock the wedge body 19 upwardly whereby the clamping ring 14 will bereleased and the upper prop member 11 will due to its own weight sinkdownwardly.

According to the embodiment shown in Figs. 6, 6a and 7, the tighteningdevice is provided with a fork-shaped portion 29 the ends of which areprovided with jaws 30, 30a respectively. These jaws catch from above andbelow behind the ears 16b of the clamping ring 1411, whereas the pistonrod 31 connected to the piston 32 due to fluid pressure admitted throughpipe 33 acts through a collar 34 connected to piston rod 31 upon the ear16b. In this way, the ears 16b and 16b are moved toward each otherthereby bringing about a tightening of the clamping ring 14b. The wedge36 will then move downwardly in a slot provided in bolt 35 which isconnected to the ear 16b. In this way the lock is latched or locked inits respective tightened position. After the wedge 36 has latched thelock, the pressure fluid may be relieved fromthe cylinder 29a so thatthe piston rod 31 may be pushed back and the entire tightening deviceincluding the cylinder 29a with fork 29 and jaws 30, 30a may be removedfrom the mine prop while the latter remains in its operative positiondue to the wedge 36. The tightening device may then be used fortightening the lock of another mine prop. i

As has been particularly clearly shown in Fig. 7, those points where thejaws of the tightening element or the latching bolts are effective uponthe ears 16b and 16b are located in the same plane.

According to the arrangement shown in Figs. 8 and 9, the piston rod 310of the piston 320 is provided with a head 37 which is located within thejaw 38 which latter angst-s is connected to one end of the bolt 35c. Ifpressure fluid is conveyed into the cylinder 29c through the conduit330, the piston rod 31c will pull the bolt 35c toward the left withregard to Fig. -8 thereby also moving the ear 16c which is connected tobolt 35c toward the left. Similarly the pressure acting in the cylinder29c moves the fork-shaped portion 39 toward the right thereby causingthe ear 16c engaged by the fork-shaped portion 39 to move toward theright so that the ears 16c and 160 are moved toward each other thereby'ghtening the clamping ring. This :arangement is furthermore providedwith a wedge 40 which in its effect corresponds to the wedge 36 of Fig.6a and extends through a corresponding slot 50. This wedge 40 bringsabout the locking or latching of the clamping device.

The tightening device according to Figs. 10, 10a and 11 is likewise sodesigned that one of the two cars namely the ear 16a! is grasped by thejaws 30d of the fork-shaped portion 29d, whereas the piston 32d hasconnected thereto a hollow piston rod 41 which is adapted to engage theear 16d. Extending into the hollow piston 41 is a bolt 46 which extendsinto the cylinder head 51 which latter is provided with a threaded bore52. The threadedbore '52 'isengaged by a correspondingly threaded bolt53 provided with a handle 45.

If pressure fluid is admitted through conduit 37 into the cylinder 42,the ears 16d and 16d are moved toward each other. When the lock isproperly tightened, the threaded bolt 53 by means of the handle 45 isrotated so as to cause the bolt 46 to engage the end wall 41d of thehollow piston rod 41. In this way, the tightening device is mechanicallylocked so that the pressure fluid may be released from the cylinder 42.

The arrangement according to Figs. 10, 10a and 11 is furthermoreprovided with sealing means 43 and 44 to prevent pressure fluid fromentering the interior of the tightening elements, especially the thread52 in the cylinder head 51.

It is, of course, to be understod that the present invention is, by nomeans, limited to the particular construct-ions shown in the drawingsbut also comprises any modifications within the scope of the appendedclaims.

What I claim is:

l. A two-part mine prop comprising inner and outer telescoping members,a clamping element carried by the telescoping end of the outer memberoperable to clamp the inner member to secure said members againsttelescoping movement, a force applying device adjustable to exert adesired force engageable with said clamping element to actuate saidelement to clamp said inner member, and a locking member movable toengage said clamping element to lock said clamping element uponactuation to clamp said inner member.

2. In combination in a lock arrangement for a mine prop having a firstprop member and a second prop member telescopically movable in saidfirst prop member: clamping ring means carried by said first prop memberand adapted to be tightened to thereby clamp said prop members togetherin their respective relative position, pressure fluid operable meansdetachably supported by one of said prop members and detachably engagingsaid clamping ring means, said pressure fluid operable means beingoperable to tighten said clamping ring means, and mechanical lockingmeans engaging said clamping ring means and operable mechanically tolock said clamping ring means in the tightened position into which itwas moved by said pressure fluid operable means and to hold saidclamping ring means in said tightened position regardless of the statusof operation of said pressure fluid operable means.

3. An arrangement according to claim 1, in which said pressure fluidoperable means and said mechanical locking means are arranged to actupon said clamping ring means in substantially one and the same plane.

4. In combination in a lock arrangement for a mine pnop having a firstprop member and a second prop member telescopically movable in saidfirst prop member: clamping ring means carried bysaid first prop memberand adapted to be tightened to thereby clamp said prop members togetherin their respective relative poistion, pressure fluid operable meanssupported by one of said prop members and operable to engage saidclamping-ring means for tightening the same, pressure relief valve meansassociated with said pressure fluid operable means for limiting thetightening force exerted by said pressure fluid operable means upon saidclamping ring means to a predetermined value, and mechanicallocking'rneans for engaging said clamping ring means and formechanically locking said clamping ring means in tightened position ofthe latter. V

5. In combination in a lock arrangement tor a mine prop having a lowerprop member and an upper prop member telescopically movable in saidlower prop'member: an open clamping ring member having its free endsprovided with ears spaced from each other and being connected to saidlower prop member, the cross section of said clamping ring memberincreasing from said ears toward a line substantially opposite thegap'between said ears, a fluid pressure cylinder piston assemblysupported by said lower prop member and operable to engage said ears andto move the same toward each other to thereby tighten said clamping ringmember and effecting frictional connection between said prop members,and mechanical locking means biased to engage said clamping ring memberand mechanically to lock the same in its respective tightened position.

6. In combination in a lock arrangement for a mine prop having a firstprop member and a second prop member telescopically movable in saidfirst prop member: anopen clamping ring having its free ends providedwith ears extending outwardly, said clamping ring being carried by saidfirst prop member and being adapted to be tightened to thereby clampsaid prop members together and to hold the same in frictional engagementwith each other, pressure fluid operable means supported by one of saidprop members, power conveying means operatively connected to saidpressure fluid operable means and arranged to convey clamping pressurefrom said pressure fluid operable means to said clamping ring throughsaid ears, and a frame-like locking member having a trapezoidal cutoutwith the inclined sides thereof arranged for engagement with said earsand movable relative to said ears to hold said ring in its respectivetightened position.

7. In combination in a lock arrangement for a mine prop having a lowerprop member and an upper prop member telescopically movable in saidlower prop member: an open clamping ring member having its free endsprovided with a first ear and a second ear spaced from each other, saidclamping ring member being connected to said lower prop member, acylinder carried by said lower prop member and adapted to receivepressure fluid, a piston reciprocably mounted in said cylinder, a pistonrod connected to said piston, a bolt extending through and in slidingengagement with said ears, said bolt being operatively connected to saidpiston and having a slot therethrough, the outer end of said bolt beingprovided with abutment .means for engagement with said second ear, saidcylinder having arms for engagement with said first ear, and awedge-shaped locking member extending through said slot.

8. In combination in a lock arrangement for a mine prop having a lowerprop member and an upper prop member telescopically movable in saidlower prop member: an open clamping ring member having its free endsprovided with a first ear and a second ear spaced from each other, saidclamping ring member being connected to said lower prop member, acylinder carried by said lower prop member and adapted to receivepressure fluid, a piston reciprocably mounted in said cylinder, a pistonrod connected to said piston and to said first ear of said =clampingring member, said cylinder being provided with arms for engagement withsaid second ear, a bolt slidably extending through said second ear andconnected to said first ear, said bolt being provided with a slotbetween the outer end of said bolt and said second ear, and a wedgemember having a tapered side and extending through said slot.

9. In combination in a lock arrangement for a mine prop having a firstprop member and a second prop member telescopically movable in saidfirst prop member: an open clamping ring member carried by said firstpro-p member and adapted to be tightened to thereby clamp said propmembers together in their respective relative position, said clampingring member having its open ends provided with outwardly extending ears,a cylinder adapted to receive pressure fluid, a piston reciprocablymounted in said cylinder, a piston rod connected to said piston, and apair of arms pivotally interconnected in a plier-like manner and havingone end thereof pivotally connected to said cylinder and said piston rodrespectively and having the other ends respectively in engagement withsaid ears for moving said ears toward each other in response to pressurefluid entering said cylinder and eifecting relative movement betweensaid cylinder d and said piston to thereby move said ears toward eachother and tighten said clamping ring member.

10. A two-part mine prop comprising inner and outer telescoping members,a clamping ring carried by the telescoping end of the outer section andcontractible to engage and clamp the inner section, a locking memberReferences Cited in the file of this patent UNITED STATES PATENTS2,433,413 Williams Dec. 12, 1950 FOREIGN PATENTS 7 921,563 Germany Dec.20, 1954 927,146 Germany May 2, 1955 1,027,658 France May 13, 1953UNITED STATES PATENT OFFICE CERTIFICATION OF CORRECTION Patent No,2,953,343 September 20 1960 Wilhelm Ludwig Gustav Heusner It is herebycertified that error appears in the above numbered patent requiringcorrection and. that the said Letters Patent should read as M correctedbelow.

In the grant, line 1, and in the heading to the printed specification,line 3, name of inventor, "Wilhelm Ludwig Gustav He'dsner", eachoccurrence read Wilhelm Ludwig Gustav Heusner in the drawings, Sheets 1to 4, in the headings thereof name of inventor, for W. L. G. Heiisner",each occurrence read W. L. G. Heusner Signed and sealed this 25th day ofApril 1961.

(SEAL) Attestz- ERNEST W. SWIDER. DAVID L. LADD Attesting OfficerCommissioner of Patents

